Abstract:Introduction: The Perseverative Thinking Questionnaire (PTQ) measures repetitive negative thinking and has been translated and validated in several countries. However, the PTQ has not been translated and validated in a Danish clinical sample. The aim of this paper was to evaluate the psychometric properties of the PTQ in a Danish clinical population and to introduce a shorter, 9-item version of the PTQ, the PTQ-9. Methods: Participants were recruited from a multicenter randomized clinical trial (N = 251). They all completed the PTQ and World Health Organization 5-item Wellbeing Index (WHO-5). Participants were further assessed with the 6-item Hamilton Anxiety Rating Scale (HAM-A6) and the 6-item Hamilton Depression Rating Scale (HAM-D6). Results: The 2nd order factor model with one higher order general factor and three lower order factors showed the best model fit for the PTQ and the PTQ-9. Both versions showed good internal consistency and the expected correlations with the constructs used for validation. Furthermore, using WHO-5 as primary outcome, both the PTQ and PTQ-9 versions were able to discriminate between treatment responders and nonresponders. Conclusion: The PTQ and the PTQ-9 showed satisfying psychometric properties in a Danish clinical sample, including sensitivity to change, and could be used to evaluate psychotherapeutic treatment. To minimize the burden for the patients, the PTQ-9 may be recommended for clinical use over the PTQ.

Negative thinking is a natural part of life. It is usually triggered when mood is low or when we have not reached the valued goals we intended to. However, negative thinking is also well-known to be involved in mental distress. In particular, repetitive negative thinking has been linked to psychopathology, including depression and anxiety disorders (Harvey et al., 2004).

Repetitive negative thinking (RNT) has been identified as a process of prolonged and recurrent negative thinking about oneself, feelings, personal concerns, and upsetting experiences (Watkins, 2008). Initially, the response styles theory conceptualized RNT as a psychopathological process linked to depression, labeled depressive rumination, and defined it as a process of repetitive thinking about the symptoms, causes, circumstances, meanings, implications, and consequences of depressed mood and distress (Nolen-Hoeksema, 1991). Over the past decade, accumulating evidence has substantiated that RNT is a central transdiagnostic factor in the development and maintenance of a range of psychopathologies and contributes to intensifying and prolonging negative mood states, interference with problem-solving, and increased avoidance behaviors (Watkins & Roberts, 2020).

In the context of several disorders, RNT has been defined in disorder-specific ways (e.g., rumination for depression, worry for generalized anxiety disorder) which does not capture RNT independently of the content of the thinking. The first measure to assess RNT as a transdiagnostic content-independent construct was the Perseverative Thinking Questionnaire (PTQ; Ehring et al., 2011). In the PTQ, RNT was defined as a style of thinking about one’s problem (current, past, or future) or negative experiences (past or anticipated) with three key characteristics: (1) being repetitive, intrusive, and uncontrollable; (2) perceived as unproductive; and (3) capturing mental resources.